You want to buy a washing machine, and a salesperson tells you that the mean repair costs for Model A and Model B are equal. You research the repair costs. The mean repair cost of 22 Model A washing machines is $208. Assume the population standard deviation is $17. The mean repair cost of 28 Model B washing machines is $228. Assume the population standard deviation is $24. At a = 0.01, can you reject the salesperson's claim? Assume the samples are random and independent, and the populations are normally distributed. Complete parts (a) through (e). The critical value(s) is/are - 2.58,2.58 . (Round to two decimal places as needed. Use a comma to separate answers as needed.) What is/are the rejection region(s)? Select the correct choice below and fill in the answer box(es) within your choice. (Round to two decimal places as needed.) z< - 2.58 , z> 2.58 O B. z< O C. z> (c) Find the standardized test statistic z for µ - H2. Z = (Round to two decimal places as needed.)

You want to buy a washing machine, and a salesperson tells you that the mean repair costs for Model A and Model B are equal. You research the repair costs. The mean repair cost of 29 Model A washing machines is $211. Assume the population standard deviation is $15. The mean repair cost of 26 Model B washing machines is $216. Assume the population standard deviation is $25. At a = 0.01, can you reject the salesperson's claim? Assume the samples are random and independent, and the populations are normally distributed. Complete parts (a) through (e). O A The mean repair cost for Model A is greater than Model B B. The mean repair costs for Model A and Model B are equal. O C. The mean repair cost for Model A is less than Model B O D. The mean repair costs for Model A and Model B are different. Let u, be the mean repair cost for Model A and let u, be the mean repair cost for Model B. What are Ho and H,? O B. Ho: H1 =H2 Hai H1 # H2 O E. Ho: H1 # H2 OC. Ho: H1 SH2 Hai H1>H2 OF. Ho: H1ZH2 Ha:…

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. According to the standard deviation rule, almost 2.5% of the students spent more than what amount of money on textbooks in a semester? A. O $195 B. $215 C. $235 D. $275 E. $295

In nutrition, the recommended daily allowance of vitamins is a number set by the government to guide an individual's daily vitamin intake. Actually, vitamin needs vary drastically from person to person, but the needs are closely approximated by a normal curve. To calculate the recommended daily allowance, the government first finds the standard deviation and the average need for vitamins among people in the population. The recommended daily allowance is then defined as the mean plus 2.7 times the standard deviation. What fraction of the population will receive adequate amounts of vitamins under this plan? Click here to see page 1 of the table for areas under the standard normal curve. Click here to see page 2 of the table for areas under the standard normal curve. The fraction of the population that will receive adequate amounts of vitamins under the given plan is (Type an integer or decimal rounded to the nearest thousandth as needed.)

In a study of speed​ dating, male subjects were asked to rate the attractiveness of their female​ dates, and a sample of the results is listed below ​(1equals=not ​attractive; 10equals=extremely ​attractive). Construct a confidence interval using a 9090​% confidence level. What do the results tell about the mean attractiveness ratings of the population of all adult​ females?   55​, 88​, 11​, 1010​, 66​, 55​, 66​, 77​, 88​, 1010​, 66​, 88    What is the confidence interval for the population mean muμ​?

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

Parents of teenage boys often complain that auto insurance costs more, on average, for teenage boys than for teenage girls. A group of concerned parents examines a random sample of insurance bills. The mean annual cost for 36 teenage boys was $672. For 23 teenage girls, it was $559. From past years, it is known that the population standard deviation for each group is $180. Determine whether or not you believe that the mean cost for auto insurance for teenage boys is greater than that for teenage girls. Conduct a hypothesis test at the 5% level. State the distribution to use for the test. (Round your answers to two decimal places.) What is the test statistic? (If using the z distribution round your answer to two decimal places, and if using the t distribution round your answer to three decimal places.) What is the p-value? (Round your answer to four decimal places.) i. ii. ii.

The mean score for first exam in your first organic chemistry class (section A) was 60, with a standard deviation of 5. Your score on the exam was 70. A. How many standard deviations above the mean is your score?

I was wondering if these answers are correct. Explain.  A study by Quadrant Information Services commissioned by Insure.com  calculated auto insurance rates for each of the 50 states; and as a result, the average annual rate for the United States was $1,317. Suppose annual rates of auto insurance in the United States are normally distributed with a standard  deviation of $324. According to MoneyGeek, a state minimum auto insurance policy in Florida costs an average of $1123 per year and the average cost of full coverage car insurance in Florida is $2208. What percentage of policies cost less than the Florida state minimum policy of $1123? z = (x - mu) / sigma z = (1123-1317)/324 z= -0.59876543 P-value from Z-Table: P(x<1123) = 0.27466 The answer is less than I expected. After using a z-table to determine the score it results in 27% of policies that are less than the minimum policy of 1123.   What percentage of auto insurance rates would be less than $1,200? z = (x - mu) / sigma…

the average hourly wage of production workers in manufacturing in 2007 was $17.41.Assume the variable is normally distributed. If the standard deviation of earning is$3.72, find the percent of production workers who Earned more than $18.55